Variable speed belt drive



Jan. 7, 1964 J. BOCHAN VARIABLE SPEED BELT DRIVE 2 Sheets-Sheet 1 Filedma 9, 1963 mmvroa JOHN BOCHAN By W F'IQI H us ATTORNEY Jan. 7, 1964Filed May 9, 1963 J. BOCHAN 3,116,644- VARIABLE SPEED BELT DRIVE 2Sheets-Sheet 2 O a, A 37 4 37 ,5 31. 22 4 '32 5s 3 es-- 8| F. G 2INVENTOR.

JOHN BOCHAN BYMPa/M Hxs ATTORNEY United States Patent 3,116,644 VARHABLESPEED BELT DRIVE John Bochan, Louisville, Ky., assignor to GeneralElectric Company, a corporation of New York Filed May 9, 1963, Ser- No.279,218 Claims. (Cl. 74-23017) This invention relates to belt drives,and more particularly to an improved variable speed belt drive.

It is an object of my invention to provide, in the type of variablespeed belt drive where the plates of one sheave are shiftable relativeto each other to vary the radius of the sheave at which the beltrotates, improved means for selectively effecting this variation.

In carrying out my invention in one form thereof, I provide a variablespeed belt drive in which a first pair of axially aligned sheave platesis rotatably mounted on a base so as to form a generally V-shapedbelt-receiving annular groove between them. A second pair of similarsheave plates is also mounted on the base with their axis of rotationremoved from the axis of rotation of the first pair, and an endlessflexible belt is seated in the grooves of the pairs of sheave plates andlinks them. At least one sheave plate of one of the pairs is axiallymovable relative to the other sheave plate of that pair, and is biasedtoward it, so that the rotational speed relationship of the two pairs ofsheave plates may be varied. The first pair of sheave plates is mountedfor movement toward and away from the second pair so as to causemovement of the axially movable sheave plate, and biasing means are provided to bias the first pair to a first distance from the second pair.

This biasing means may be overcome by speed changing means which,according to my invention, includes a ratchet which is secured to movewith the first pair, and is engageable by a pawl mounted on a supportmember pivotally secured to the second pair eccentrically of the axisthereof. This support member is provided with a guide so that it hasreciprocating motion during rotation of the second pair. The pawl isnormally biased out of engagement with the ratchet; electricallyactuated means are also mounted on the support means, and connected tothe pawl so that energization of the electrically actuated means movesthe pawl into engagement with the ratchet.

The pawl and ratchet are so formed that the ratchet is moved in adirection opposite to the bias of the biasing means during rotation ofthe second pair and energization of the electrically actuated means.This has the result that energization of the electrically actuated meanscauses the speed relationship to be changed from that which prevailswhen the first pair is in the position to which it is biased by thebiasing means; the changed speed relationship will prevail as long asthe electrically actuated means remains energized.

The subject matter which I regard as my invention is particularlypointed out and distinctly claimed in the concluding portion of thisspecification. My invention itself, however, may best be understood byreference to the following description taken in conjunction with the accompanying drawings.

in the drawings, FlGURE l is a rear elevational view of a typicalmachine, in this case a combination clothes washing and drying machine,in which my novel variable speed belt drive is incorporated, the viewbeing partly in section and partly broken away to show details; and

FIGURE 2 is a side elevational view of the machine of FIGURE 1, partlyin section and with certain surfaces broken away to show details.

Referring now to the figures of the drawings, there is shown acombination clothes Washing and drying machine wherein the operatingelements of the machine are included within an outer cabinet structurehaving a 3,ll6,64 i Patented Jan. 7, 1964 central wrap-around section 1.Section 1 is supported on a base assembly 2 and carries a separate top 3on which is supported a backsplasher and control panel 4. Access to theinterior of the machine is provided by a door 5 formed in section 1, thedoor being mounted on suitable hinges (not shown) and being opened byany suitable means such as a latch control 6.

The machine has a clothes basket or container 7 mounted for rotation ona generally horizontal axis within an outer enclosing stationary tubstructure 8. Basket 7 comprises a cylindrical outer wall 9 provided witha plurality of suitably spaced perforations -10 to allow air and watercommunication between the interior and the exterior of the basket 7. Therear of the basket is closed by means of a suitable wall or plate 11.The basket also includes a front wall 12 which is formed so as to definean access or loading opening 13 in registry with an opening 14 inWrap-around section 1 provided for door 5.

The container is rotatably supported by a shaft 15 which is mounted inan elongated bearing 16 supported from rear wall 17 of tub 8. The tub isalso provided with an opening 18 aligned with openings 13 and 14 so thatclothes may be placed into and removed from the basket when door 5 isopened. The door seals against a suit able gasket 19 during operation ofthe machine.

During operation of the machine the basket 7 is driven from an electricmotor 20 to which is secured a pulley 21 driving a conventional endlessflexible belt 22. Belt 22 has a truncated V-shaped cross section, asbest shown in FIGURE 2. Through the improved belt drive of my invention,which Will be described herebelow, the motor 20 effects the rotation ofa belt 23 driving a sheave 24 connected to shaft 15 at either high speedor low speed. For instance, a relatively low speed such as 47 rpm. maybe provided to the basket for tumbling clothes in the basket duringwashing and drying operations. However, during the centrifugal spinextraction which is conventional in such machines, the speed of thebasket is raised to 30 0 rpm. so as to permit the centrifugal extractionof liquid from clothes in basket 7.

It will be understood that in combination with this structure there areprovided the conventional elements of a combination washer-dryer, suchas, for instance inlet water valves for providing water for thedifferent washing and rinsing operations, drain means for removal of thewater, heating means for effecting heat drying of the clothes after awashing operation has been terminated, and control means for providingproper operation of all these elements in sequence. These elements arenot shown since they do not pertain to my inventive concept and may beof any conventional construction, many of which are commerciallyavailable at the present time.

The general structure of the variable speed drive will now be described.It has been stated that pulley 21 drives the belt 22. Belt 22, in turn,drives an adjustable sheave assembly 25. The adjustable assemblyincludes a shaft 26 to which are rigidly secured two sheave plates 27and 28. An intermediate sheave plate 29 is keyed on shaft 26 so as to bemovable along the shaft 26 to varying distances from sheave plates 27and 28. It will be observed that sheave plate 27 has a sloping surface30 which, in cooperation with sloping surface 31 on movable sheave plate29, forms a generally V-shaped groove of adjustable width. Similarly, onits other side, movable sheave Plate 29 is provided with a slopingsurface 33 which cooperates with sloping surface 34 of rigidly securedsheave plate 23 to form a second V-shaped groove 35 of adjustable width.Since belt 22 has a predetermined width, it can be seen that movement ofsheave plate 29 relative to sheave plate 27 will cause the belt 24 toseat in groove 32 at a distance from the center of shaft 26 which is 3determined by the distance of sheave plate 29 from sheave plate 27.

The linear speed of belt 22 is constant, assuming the speed of motor 29to be constant, and therefore the rotational speed of the adjustablesheave assembly 25 is dependent on the effective sheave radius providedby the cooperation of sheave plates 27 and 29, i.e., the distance atwhich belt 22 is seated. When the sheave plates 27 and 29 are in theposition shown in the figures, sheave assembly 25 is rotating at arelatively low speed. If sheave plate 29 is moved to the left, as viewedin FIG- URE 2, away from sheave plate 27, then belt 22 will move inradially toward shaft 25 as groove 32 widens, and will cause a greaterrotational speed of the sheave assembly 25 for a given rotational speedof pulley 21 by motor 29.

A second endless flexible belt 36, also having a truncated V-shapedcross section, is driven in groove by the sheave formed by thecooperation of sheave plates 29 and 28. When adjustable sheave plate 29is in the position shown so that groove 36 is quite wide, belt 36 has tomove in radially toward shaft 26 a substantial amount before it seats onthe surfaces 33 and 34 of sheave plate 29 and 28 respectively. Thismeans that for a given rotational speed of the adjustable sheaveassembly (as imparted to it by belt 22), belt 36 will be traveling at arelatively low rate of linear speed. If sheave plate 29 is moved to theleft so that belt 36 is forced outwardly in groove 35, then for a givenrotational speed of the sheave assembly a relatively high linear speedof belt 36 is provided.

Thus, by controlling the position of sheave plate 2"), an infinitevariety of speeds between the two limits of position of sheave plate 29may be provided. The arrangement shown in FIGURE 2 provides the lowestoutput speed to belt 36 since belt 22 is causing the lowest rate ofrotation of sheave assembly 25 and rotation of the sheave assembly 25 iscausing the lowest linear speed of belt 36. The highest rate of speedwill be provided if sheave plate 29 is moved as far as possible to theleft in FIGURE 2, in which case belt 22 moves inwardly as far aspossible to provide the highest rotational speed of the assembly 25 fora given linear speed of belt 22, and the output linear speed of the belt36 is the highest possible for a given rotational speed of assembly 25.It will be observed, in addition, that belts 22 and 36 each exert abiasing force on sheave plate 29, each belt tending to move the plate 29into engagement with the other belt.

Belt 36 passes over a sheave 37 which forms part of a unitary assemblywith a sheave 38 which drives belt 23. It will be understood that thesheave 37 is formed of two sheave plates 37a and 37b providing aV-shaped groove 37c between them in the same manner as described inconnection with the adjustable sheave assembly 25 except for the factthat the plates of sheave 37 are not adjustable. The belt 23 driven bysheave 3% drives sheave 24 and, as previously described, this sheave isrigidly secured to the end of shaft 15 so as to rotate basket 7.

Returning now to the adjustable sheave assembly 25, and with particularreference to FIGURE 1, it will be observed that the assembly is mountedon a mounting structure which includes a V-shaped arm assembly 39(FIGURE 2) pivotally secured on a pin 40 within a bracket 41 secured tobase 2 of the machine. A spring 42 has one end 43 secured to the machinebase and has its other end 44 secured to arm 29 so as to bias theassembly 25 to the left, as viewed in FIGURE 1.

The assembly of sheaves 37 and 38 is mounted on a linkage assembly 45pivotally mounted on a pin 46 mounted within a bracket 47 secured tobase 2. The linkage arrangement includes two arms 48 and 4% which arepivotally secured together by a pin 50. A pin 51 near the top of arm 49provides the axis of rotation for sheaves 37 and 38. A spring 52,secured at one end 53 to base 2 of the machine, is secured at its otherend 54 to the assembly of sheaves 37 and 33 so as to bias themdownwardly and to the right (as viewed in FIGURE 1) in order to effect abelt tensioning function for belts 36 and 23.

As part of my improved speed changing arrangement for the belt drivesystem described, I provide a rod-like support member 55 which has oneend 56 secured in pivotal, or rotatable, relation on the assembly ofsheaves 37 and 38 eccentrically to the axis thereof. A support, orguide, 57 may be secured on the rear Wall E7 of tub 8 so as to supportthe other end 58 of rod 55. As a result, the rod will have a primarilyreciprocating motion when there is rotation of the assembly of sheaves37 and 38 in the same manner that a piston rod is reciprocated by therotation of a crankshaft in an automobile.

Pivotally secured on a pin 59 extending from rod 55 is a pawl member 60.Pawl 60 is normally biased by a spring 61 secured to end 62 of the pawland to the rod 55 so as to be out of engagement with a ratchet 63 formedas part of the adjustable sheave assembly 25. An electrical actuatingassembly, is provided which, in the embodiment shown, comprises asolenoid assembly 64 with a plunger 65 which is drawn into the solenoidassembly, that is, to the left as shown in FIGURE 1, when the solenoidis energized. When this occurs, the solenoid overcomes the action ofspring 61 and causes pawl 60 to be pivoted about pin 5 into engagementwith ratchet 63. It will be observed that the teeth of ratchet 63 are soformed that the right side of each tooth is sloped so as to permit thepawl to slide over the tooth, while the left side is substantiallyvertical so as to retain the ratchet when it bears against that surface.

When the solenoid 64 is not energized, pawl 65 is out of engagement withratchet 63 and consequently the spring 42 is effective to maintain theadjustable sheave assembly 25 in the position shown, in a positiontoward the left as viewed in FIGURE 1 so as to provide a minimum outputspeed to the basket as previously described.

When it is described to increase the speed of the basket, solenoid 64 isenergized. This pivots pawl 60 down into engagement with the teeth ofratchet 53. Upon each movement of rod 55 to the right, as a result ofits eccentric mounting on the assembly of sheaves 37 and 38, pawl 6t}will pull the ratchet 63 to the right a small amount at a speed fasterthan that at which spring 42 is capable of pulling ratchet 63 to theleft. As the rod reciprocates back to the left because of the continuedrotation of the assembly of sheaves 37 and 38 the pawl will slide upover the slanted right hand surface of a tooth of ratchet 63 so as to bein position to pull the adjustable sheave assembly 25 a little fartheragain upon the next reciprocating movement to the right of the rod 55.Because the spring 42 pulls the ratchet quite slowly, the ratchet is notmoved back to the left far enough, when the pawl is sliding over atooth, to impede this movement of the assembly to the right. In thisway, after a number of rotations of the assembly of sheaves 37 and 38,the engagement of pawl 60 with ratchet 63 will have caused the pawl topull the ratchet, and therefore the entire assembly 25, a substantialdistance to the right as viewed in FIGURE 1. As explained, this has thedual effect of increasing the speed transmitted from motor 20 toassembly 25, and from assembly 25 to the assembly of sheaves 37 and 38.

Of course, as soon as it is desired to return to tumble, it is merelynecessary to de-energize the solenoid, at which point the spring 51 willmove pawl 60 out of engagement with the ratchet and the spring 42 willpull the assembly back to the left to lower the output speed of thesystem. It will be seen from the foregoing that my invention provides anovel and simple means of achieving the speed variations desired in avariable speed belt drive. Among other advantages, a very smallinexpensive solenoid may be used.

While in accordance with the patent statutes I have described what atpresent is considered to be the preferred embodiment of my invention, itwill be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the invention,and I therefore aim in the appended claims to cover all such changes andmodifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. A variable speed belt drive comprising:

(a) a base;

(b) a first pair of axially aligned sheave plates rotatably mounted onsaid base and forming a generally V- shaped annular groove between them;

(0) a second pair of axially aligned sheave plates rotaably mounted onsaid base with their axis of rotation removed from the axis of rotationof said first pair and forming a generally V-shaped annular groovebetween them;

(d) an endless flexible belt seated in said grooves and linking said twopairs;

(2) at least one of said sheave plates of one of said pairs beingaxially movable relative to the other sheave plate of said pair andbiased theretoward thereby to vary the speed relationship of said pairs;

(f) mounting means positioning said first pair for movement toward andaway from said second pair so as to cause movement of said axiallymovable sheave plate;

(g) first biasing means connected to said mounting means to bias saidfirst pair to a first distance from said second pair;

(11) and speed changing means for overcoming said first biasing meanscomprising;

(i) a ratchet secured on said mounting means, (ii) a support memberpivotally secured to said second pair eccentrically of the axis thereof,(iii) a guide supporting said support member for reciprocating motion,

(iv) a pawl movably mounted on said support member and engageable withsaid ratchet,

(v) second biasing means biasing said pawl out of engagement with saidratchet,

(vi) electrically actuated means mounted on said support means andconnected to said pawl, said electrically actuated means being arrangedso that when energized said electrically actuated means moves said pawlinto engagement with said ratchet,

(vii) said pawl and said ratchet being formed to move said ratchet in adirection away from the bias of said first biasing means during rotationof said second pair and energ-ization of said electrically actuatedmeans.

2. The apparatus defined in claim 1 wherein said two pairs of sheaveplates have their axes parallel to each other, and said electricallyactuated means is a solenoid.

3. The apparatus defined in claim 1 wherein said first biasing meanscomprises a spring connected between said mounting means and said baseso as to bias said first pair away from said second pair, said ratchetand pawl being formed to cooperate to pull said first pair toward saidsecond pair against the action of said spring.

4. The apparatus defined in claim 1 wherein said pawl is pivotallymounted on said support member so as to be pivotable between a positionin which it engages said ratchet and a position in which it isdisengaged from said ratchet.

5. The apparatus defined in claim 1 wherein said first pair includessaid axially movable sheave plate.

Schmied Sept. 3, 1946 Buss Dec. 18, 1962

1. A VARIABLE SPEED BELT DRIVE COMPRISING: (A) A BASE; (B) A FIRST PAIROF AXIALLY ALIGNED SHEAVE PLATES ROTATABLY MOUNTED ON SAID BASE ANDFORMING A GENERALLY VSHAPED ANNULAR GROOVE BETWEEN THEM; (C) A SECONDPAIR OF AXIALLY ALIGNED SHEAVE PLATES ROTAABLY MOUNTED ON SAID BASE WITHTHEIR AXIS OF ROTATION REMOVED FROM THE AXIS OF ROTATION OF SAID FIRSTPAIR AND FORMING A GENERALLY V-SHAPED ANNULAR GROOVED BETWEEN THEM; (D)AN ENDLESS FLEXIBLE BELT SEATED IN SAID GROOVES AND LINKING SAID TWOPAIRS; (E) AT LEAST ONE OF SAID SHEAVE PLATES ON ONE OF SAID PAIRS BEINGAXIALLY MOVABLE RELATIVE TO THE OTHER SHEAVE PLATE OF SAID PAIR ANDBIASED THERETOWARD THEREBY TO VARY THE SPEED RELATIONSHIP OF SAID PAIRS;(F) MOUNTING MEANS POSITIONING SAID FIRST PAIR FOR MOVEMENTS TOWARD ANDAWAY FROM AXIALLY MOVABLE SHEAVE PLATE; (G) FIRST BIASING MEANSCONNECTED TO SAID MOUNTING MEANS TO BIAS SAID FIRST PAIR TO A FIRSTDISTANCE FROM SAID SECOND PAIR; (H) AND SPEED CHANGING MEANS FOROVERCOMING SAID FIRST BIASING MEANS COMPRISING; (I) A RATCHET SECURED ONSAID MOUNTING MEANS; (II) A SUPPORT MEMBER PIVOTALLY SECURED TO SAIDSECOND PAIR ECCENTRICALLY OF THE AXIS THEREOF; (III) A GUIDE SUPPORTINGSAID SUPPORT MEMBER FOR RECIPROCATING MOTION, (IV) A PAWL MOVABLYMOUNTED ON SAID SUPPORT MEMBER AND ENGAGEABLE WITH SAID RATCHET, (V)SECOND BIASING MEANS BIASING SAID PAWL OUT OF ENGAGEMENT WITH SAIDRATCHET, (VI) ELECTRICITY ACTURATED MEANS MOUNTED ON SAID SUPPORT MEANSAND CONNECTED TO SAID PAWL, SAID ELECTRICALLY ACTUATED MEANS BEINGARRANGED SO THAT WHEN ENERGIZED SAID ELECTRICALLY ACTUATED MEANS MOVESSAID PAWL INTO ENGAGEMENT WITH SAID RATCHET, (VII) SAID PAWL AND SAIDRATCHET BEING FORMED TO MOVED SAID RATCHET IN A DIRECTORY AWAY FROM THEBIAS OF SAID FIRST BIASING MEANS DURING ROTATION OF SAID SECOND PAIR ANDENERGIZATION OF SAID ELECTRICITY ACUTATED MEANS.